Observation of the nuclear magnetic octupole moment of [sup.87]Rb from spectroscopic measurements of hyperfine intervals

The magnetic octupole moment of [sup.87]Rb is determined from hyperfine intervals in the 5p ²[P.sub.3/2] state measured by Ye et al. Opt. Lett. 21, 1280 (1996). Hyperfine constants A = 84.7189(22) MHz, B = 12.4942(43) MHz, and C = -0.12(09) kHz are obtained from the published measurements. The existence of a significant value for C indicates the presence of a nuclear magnetic octupole moment Ω. Combining the hyperfine constants with atomic structure calculations, we obtain Ω = -0.58(39) b[μ.sub.N]. Second-order corrections arising from the interaction with the nearby 5p ²[P.sub.1/2] state are found to be insignificant. PACS Nos.: 21.10.Ky, 32.10.Fn, 42.62.Fi Nous determinons le moment magnetique octupolaire du [sup.87]Rb a partir des intervalles hyperfins dans l'etat 5p ²[P.sub.3/2] mesures par Ye et al. (Opt. Lett. 21, 1280 (1996)). A partir de ces valeurs publiees, nous avons extrait les constantes hyperfines A = 84.7189(22) MHz, B = 12.4942(43) MHz et C = -0.12(09) kHz. Le fait que C ne soit pas nul indique l'existence d'un moment magnetique nucleaire octupolaire Ω. En combinant les constantes hyperfines extraites avec des calculs de structure atomique, nous obtenons Ω = -0.58(39) b[μ.sub.N]. Nous trouvons que les corrections du second ordre provenant de l'interaction avec l'etat proche 5p ²[P.sub.1/2] sont negligeables. [Traduit par la Redaction]
1. Introduction We report values of the nuclear magnetic octupole moment of [sup.87]Rb determined from measured hyperfine intervals. During an earlier investigation of the hyperfine structure of atomic [sup.133]Cs [1], [...]